Risk of premature death 9-fold among illicit drug users

Premature deaths are almost nine times more common among illicit drug users than among the general Finnish population, shows a new study from the University of Eastern Finland. The excess mortality is especially pronounced among female drug users, according to findings presented by Ifeoma Onyeka, MSc, in her doctoral dissertation. The most common causes of death were accidental overdose and suicide. The risk for all-cause death was the highest among intravenous drug users.

The study assessed deaths occurring among treatment-seeking drug users in the Greater Helsinki Area of Finland. Specifically, the study examined causes of death, potential years of life lost before 70 years, and the risk/association between the route of drug administration and all-cause deaths.

The study used data available in the national drug treatment database HUUTI, containing the medical records of 4,817 consecutive drug-using clients, 3,365 males and 1,452 females, aged 11-65 years who sought treatment at the Helsinki Deaconess Institute (HDI) between 31 January 1997 and 31 August 2008. Their data were linked to the Finnish National Cause of Death Register and they were followed-up from the first day of their first visit to HDI until death or 31 December 2010, whichever came first.

A total of 496 out of the 4,817 clients (10.3%) died during the follow-up. Of these 496 deaths, 417 (84.1%) occurred in male drug users and 79 (15.9%) in females. Deaths in the entire cohort were almost nine-fold of those that occurred in the general Finnish population of the same age and gender. This excess mortality was more pronounced among females than males. Overall, the most common causes of death were accidental overdose (165 deaths) and suicides (108 deaths), followed by deaths from mental and behavioural disorders (49 deaths) and circulatory system diseases (45 deaths).

The study found that clients died prematurely at the average (mean) age of 33.8 years. The average (mean) potential years of life lost per decedent before the age of 70 years was 36.2 years. On average, female drug users lost more life years than their male counterparts but men lost the highest total number of life years. The two top-ranking causes of lost life years were accidental overdose and suicide.

Further analyses were carried out in a subset of clients who reported opiates and stimulants as their primary drug at baseline interview. Among clients whose routes of drug administration were specified, intravenous (I.V.) drug users had higher proportions of all-cause deaths (12.7%, n=251/1976), followed closely by oral users (11.5%, n=27/235) while smokers and snorters came a distant third (7.9%, n=12/152) and fourth (6.9%, n=19/276) respectively. The risk for all-cause death was lower among smokers compared to I.V. users (adjusted hazard ratio: 0.52 [95%CI: 0.28-0.97]) after adjusting for gender, homelessness, number of drugs used, type of primary drug, past month frequency of using primary drug, and psychiatric problems present at initial visit.

The study demonstrated that prevention and intervention measures that address accidental overdose and suicide would be necessary in order to reduce untimely deaths among drug users, thereby stemming the preventable loss of potential future workforce. Gender-specific approaches will be required to address the treatment needs of female drug users. Granted that smokers had a lower risk of all-cause death than injectors, it does not necessarily imply that smoking is a harmless way to use drugs.

The findings were originally published in Journal of Addictive Diseases, International Journal of Drug Policy, Journal of Community Health, and Journal of Substance Use 2015.